We have been taught that unit tests should be repeatable and most people (including the author) for a long time considered this an equivalent to "static", single-path execution. Solr and Lucene employ an interesting JUnit runner strategy where tests are randomized -- run with various data, various implementation of allowed interfaces, various configurations. The number of combinations makes running them all impossible, but execution randomization proves very successful at pinpointing implementation and regression bugs. This talk will provide an overview of this approach and practical considerations on when and how to port them to your own projects. Everything that stems from Lucene/Solr is not directly connected to search/ document retrieval and can still be useful and reused in other projects. This session is probably best suited to developers/ CTOs.